Screening of the newborns helped diagnose congenital hypothyrosis in infants of Moscow and define its incidence as 1 per 5000 newborns. Seventeen newborns (20%) with congenital hypothyrosis were detected among 65 ones with positive tests of more than 5 microU/ml. Clinical manifestations of this disease may be detected by specialists within the first weeks of life. Blood TTH level higher than 100 microU/ml is an evidence of congenital hypothyrosis, though one case with a lower TTH level in a newborn was detected. Levothyroxine therapy in a daily dose 50 micrograms is the optimal for the majority of such patients. For infants with transitory hypothyrosis with blood TTH levels from 40 to 80 micrograms/ml short levothyroxine therapy courses in daily doses 25-50 micrograms for 2-3 weeks may be recommended to preserve the intellectual potential of the child. All the children with blood TTH levels higher than 20 microU/ml should be regularly examined by endocrinologists and neuropathologists starting from the first days of life.